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electric field value is 0 and current density's scale is different in flux

Hi, I'm studying electromagnetic analysis of motors using FLUX.
According to my studies, an electric field should exist if the magnetic flux density changes over time (based on the Maxwell-Faraday principle).

However, as shown here, there is no electric field, even though the magnetic flux density changes over time due to the rotor's rotation. (I have already exported the node values, and there is no electric field value present either.)

Additionally, I have another problem. I understand that current density can be calculated using the formula J=I/AJ = I/AJ=I/A.I calculated it manually, but the results are different from the FEM results. Even after adjusting the depth to account for discrepancies, the values decreased but the residuals between the FEM results and the theoretical results are still too large.

Is there any additional formula or factor I might be missing?

These are the two questions I want to ask. If you know the answers, I would greatly appreciate your help. Thank you!

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fzidat

Hello Nara;

In Low Frequency there is a split between Electric field and Magnetic fiel. That is why in Flux you have dedicated magnetic application and other for Electric field application. You cannot plot in magneto static or Transient Magnetic application the electric Field.

The current density is not dependent on the depth, but on the whole current perpendicular on the section considered and the section area of it.

Regards

Nara

Thank you for answering me, fzidat.

The question about Electric field is understandable, but still have wondering about current density.

I can show light yellow one as an example.

According to the formula, J=I/A,

I = 10A (at 72deg) A = 0.5 * angle_rad * (R_outer**2 - R_inner**2) * 1e-6 = 740.2*1e-6 m^2
(where R_outer, R_inner, angle_deg = 46.35, 26.59, 60)

so, J = 1.35*1e4 which is different from FEM value (2.496*1e6).

As I calculated, scale is significantly different. Is this formula wrong?

fzidat

Hello Nara,

You are welcome!

This is then a new question :)

You can compute the face area directly in Flux, right click on the face and then you can select compute face area.

The current perpendicular to the face should be the total current (so you need to includ the number of turns)

Regards